#include "apue.h"
#define BUFFSIZE 4096

int main(void)
{
    int n;
    char buf[BUFFSIZE];
    while((n = read(STDIN_FILENO, buf, BUFFSIZE)) > 0)
        if(write(STDOUT_FILENO, buf, n) != n)
            err_sys("write error");
    if(n < 0)
        err_sys("read error");
    return 0;
        
}
